BACKGROUND: Polyunsaturated fatty acids can have beneficial effects on human immune cells, such as peripheral blood mononuclear cells (PBMCs). However, the mechanisms of action of polyunsaturated fatty acids on immune cells are still largely unknown.

OBJECTIVE: The objective was to examine the effects of supplementation with the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on whole-genome PBMC gene expression profiles, in healthy Dutch elderly subjects participating in a double-blind trial, by using whole-genome transcriptomics analysis.

DESIGN: The subjects were randomly allocated to 1 of 3 groups: 1) consumption of 1.8 g EPA+DHA/d (n = 36), 2) consumption of 0.4 g EPA+DHA/d (n = 37), or 3) consumption of 4.0 g high-oleic acid sunflower oil (HOSF)/d (n = 38). All supplements were given in capsules. Before and after 26 wk of intervention, blood samples were collected. Microarray analysis was performed on PBMC RNA from 23 subjects who received 1.8 g EPA+DHA/d and 25 subjects who received HOSF capsules. Quantitative real-time polymerase chain reaction was performed in all 111 subjects.